thanks. when i get a chance i will look in to this.
is it possible that the dc leak is coming from the power supply? im
using the cgs14 built to spec with positive measuring 14.8-14.95 and
negative sitting happily on 15v. i am thinking one of my filter caps
or possibly the positive regulator isnt working right. i am thinking
that a low battery in my multimeter could also be contributing to this
reading on the positive voltage.
if its not the psu where would u trace back the dc to? i will try
installing that cap but i would rather keep it clean and to the boards
spec.
is it possible that the dc leak is coming from the power supply? im
using the cgs14 built to spec with positive measuring 14.8-14.95 and
negative sitting happily on 15v. i am thinking one of my filter caps
or possibly the positive regulator isnt working right. i am thinking
that a low battery in my multimeter could also be contributing to this
reading on the positive voltage.
if its not the psu where would u trace back the dc to? i will try
installing that cap but i would rather keep it clean and to the boards
spec.
--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> The +6V is only there as part of a bus system I was using in some of my
> panels that did require +6V - old Serge stuff mostly. 6 volts is not
used in
> any CGS board.
>
> One known cause of scratchiness showing with pots is if there is a
DC signal
> involved. I don't know if the following will help or be a total
failure, but
> try placing a 10uF electro in series with the pot to block any DC
component.
> Before you do though, us a multimeter to work out which end is more
positive
> so you get the cap in the right way around.
>
> Ken
>
>
> >
> >
> >ok so i went out and bought a new pot just to drop in in case the pot
> >i had was bad. seemed it was. i dropped it in and still its scratchy.
> >is it possible that i am wiring the legs of the pot up wrong? whilst
> >trawling the message archives i noted that ken advises that the third
> >leg of the pot is not connected hence i havent grounded it.
> >
> >i was about to try peng's suggestions but then i realised i have
> >nothing connected to the +6v pad.
> >
> >i run the ground to the frequency pot then run the ground across to
> >some perfboard where ive tied in the grounds of the input output and
> >volume pot. the 6v connector isnt used at all!
> >
> >--- In cgs_synth@yahoogroups.com, "peng3002" <peng3002@y...> wrote:
> >>
> >> Hold up before replacing the pot. I had a similar problem ith the
Res
> >> pot. It actually came from other pots/jacks not being grounded. Next
> >> to the power supply header there is a "6V" hole on the pcb. Make
sure
> >> if your using this hole to run a ground line to pots/jacks to solder
> >> a link to the ground trace right next to it. Cleared up my crackle
> >> problems, maybe it'll work for you.
> >>
> >> As far as output levels go...I took out the link and replaced it
with
> >> a 390K resistor.
> >>
> >> As a side note: I think Ken says to breadboard first. This is great
> >> advice. For instance: I built the pulse divider and it works
> >> perfectly, but it puts out 13-15volts and I would have preferred
> >> 5volts. It's simply a matter of changing some resistors to get the
> >> output level I want, but after everything is wired solder work
can be
> >> a little awkward.
> >>
> >> Phil
> >>
> >>
> >> --- In cgs_synth@yahoogroups.com, "hiriseau" <sean@p...> wrote:
> >> >
> >> > thanks i will get another one pronto, its a sealed pot so nothing i
> >> > can really do about it. and its only a couple of dollars to get a
> >> new
> >> > one.
> >> >
> >> > with the level, considering that i will be using the filter in a
> >> tweak
> >> > hard on the fly sort of role, would i be better off using the trim
> >> pot
> >> > to set the output level and then attenuator on the input, so that i
> >> > don't kill any club sound systems and peoples ears?
> >> >
> >> > --- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> >> > > >the resonance pot is EXTREMELY crackly whenever i move it.
> >> > >
> >> > > That's a dud pot. It isn't a solder issue, but rather dust or
> >> > "corrosion" on
> >> > > the pot resistive strip. A shot of electrolube contact
cleaner may
> >> > help. A
> >> > > better pot is the best solution.
> >> > >
> >> > > >secondly, levels. i have the link in and i have a 50k log
pot in
> >> (the
> >> > > >same 9mm alpha) and it doesnt seem to be working too well.
it is
> >> low
> >> > > >in volume then BANG heaps of volume. my suspicion is that i
> >> should be
> >> > > >using a linear pot instead of a log pot. this is what it sounds
> >> like
> >> > > >http://users.bigpond.net.au/xpander/level.mp3 would i be better
> >> off
> >> > > >using the pot as an attenuator on the input stage, and using a
> >> trim
> >> > > >pot on the level to tweak it to where i want?
> >> > >
> >> > > Yes, a linear pot would probably be better. In fact, I rarely use
> >> > log pots
> >> > > in synthesizers at all.
> >> > >
> >> > > Ken
> >> > >
> >> > >
> >>
______________________________________________________________________
> >> _
> >> > > Ken Stone sasami@h... or sasami@c...
> >> > > Modular Synth PCBs for sale
> >> <http://www.blaze.net.au/~sasami/synth/>
> >> > > Australian Miniature Horses & Ponies
> >> <http://www.blaze.net.au/~sasami/>
> >
> >
> >
> >
> >
> >
> >See the following URLS for the CGS Modular Synth home page:
> >Main: http://www.cgs.synth.net/
> >Secondary: http://otherunicorn.0catch.com/synth/
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
> _______________________________________________________________________
> Ken Stone sasami@h... or sasami@c...
> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>